title: Notch signaling maintains Leydig progenitor cells in the mouse testis.
abstract: During testis development, fetal Leydig cells increase their population from a pool of progenitor cells rather than from proliferation of a differentiated cell population. However, the mechanism that regulates Leydig stem cell self-renewal and differentiation is unknown. Here, we show that blocking Notch signaling, by inhibiting gamma-secretase activity or deleting the downstream target gene Hairy/Enhancer-of-split 1, results in an increase in Leydig cells in the testis. By contrast, constitutively active Notch signaling in gonadal somatic progenitor cells causes a dramatic Leydig cell loss, associated with an increase in undifferentiated mesenchymal cells. These results indicate that active Notch signaling restricts fetal Leydig cell differentiation by promoting a progenitor cell fate. Germ cell loss and abnormal testis cord formation were observed in both gain- and loss-of-function gonads, suggesting that regulation of the Leydig/interstitial cell population is important for male germ cell survival and testis cord formation.
authors.affiliation: The Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Tang
authors.forename: Jennifer
authors.initials: J
authors.lastname: Brennan
authors.forename: Jeannie
authors.initials: J
authors.lastname: Karl
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hamada
authors.forename: Lori
authors.initials: L
authors.lastname: Raetzman
authors.forename: Blanche
authors.initials: B
authors.lastname: Capel
mesh_terms: D053829:Amyloid Precursor Protein Secretases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation; D004622:Embryo, Mammalian / Q000196:embryology / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007985:Leydig Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013234:Stem Cells / Q000378:metabolism*; D000072056:Transcription Factor HES-1
chemical_list: D053829:Amyloid Precursor Protein Secretases; D051792:Basic Helix-Loop-Helix Proteins; D004791:Enzyme Inhibitors; D018398:Homeodomain Proteins; D051880:Receptors, Notch; D000072056:Transcription Factor HES-1; C489734:Hes1 protein, mouse